Door alarm



FIG. 1 is a front view of a door alarm illustrating my new design;

FIG. 2 is a side elevational view showing the left side of the door alarm;

FIG. 3 is a top view of the door alarm;

FIG. 4 is a bottom view of the door alarm; and

FIG. 5 is a front perspective view of the door alarm. 

The ornamental design for a door alarm, substantially as shown and described. 